This invention relates to winding fiber-reinforced resin products, and more particularly it relates to winding a plurality of lengths of thermoplastic resin impregnated yarns to form an insitu consolidated product.
Equipment for winding single length thermoplastic resin impregnated yarn on a mandrel is known. However, fabrication of parts in this manner is slow and costly because only one impregnated length of yarn is wound at low speed. When scale-up has been attempted, the control of multiple lengths of such yarns during winding at higher speeds above 10 ft./min. presented barriers because heating the resin to its melt temperature during winding caused sticking of the polymer to guides, loss of control of band width and fuzzing of the yarn. This resulted in unacceptable operability as well as broken filaments which gave poor mechanical properties. In addition, the inability to get enough heat into a multi-end system to melt the polymer always produced parts with an unacceptable level of voids unless the product was subject to a post heating treatment. Furthermore, these limitations have deprived end users of the lower cost improved products which could be obtained from thermoplastic resin impregnated yarn.